Create Shortcuts for Particle Edit Brushes?
I expanded gandalf3's example:

import bpy

items = [
    ("NONE"  , "None"  , "Don’t use any brush"         , 0),
    ("COMB"  , "Comb"  , "Comb hairs"                  , 1),
    ("SMOOTH", "Smooth", "Smooth hairs"                , 2),
    ("ADD"   , "Add"   , "Add hairs"                   , 3),
    ("LENGTH", "Length", "Make hairs longer or shorter", 4),
    ("PUFF"  , "Puff"  , "Make hairs stand up"         , 5),
    ("CUT"   , "Cut"   , "Cut hairs"                   , 6),
    ("WEIGHT", "Weight", "Weight hair particles"       , 7)
    ]


class PARTICLE_OT_select_brush(bpy.types.Operator):
    """Select a particle brush"""
    bl_idname = "particle.select_brush"
    bl_label  = "Particle Select Brush"

    brush = bpy.props.EnumProperty(
                name = "brush",
                default = "NONE",
                items = items
                )

    def execute(self, context):
        context.scene.tool_settings.particle_edit.tool = self.brush
        for region in context.area.regions:
            if region.type == "TOOLS":
                region.tag_redraw()
        return {'FINISHED'}


class VIEW3D_MT_particle_edit_select_brush(bpy.types.Menu):
    bl_label = "Particle Select Brush"

    def draw(self, context):
        layout = self.layout

        layout.operator_context = "INVOKE_REGION_WIN"

        for item in items:
            layout.operator(
                operator = "particle.select_brush",
                text = item[1],
                ).brush = item[0]

def register():
    bpy.utils.register_class(PARTICLE_OT_select_brush)
    bpy.utils.register_class(VIEW3D_MT_particle_edit_select_brush)

def unregister():
    bpy.utils.unregister_class(VIEW3D_MT_particle_edit_select_brush)
    bpy.utils.unregister_class(PARTICLE_OT_select_brush)

if __name__ == "__main__":
    register()

    #register keys via script
    #might be better done via user preferences
    #see image below

    wm = bpy.context.window_manager
    km = wm.keyconfigs['Blender User'].keymaps['Particle']

    keys = ("ONE","TWO","THREE","FOUR","FIVE","SIX","SEVEN","EIGHT")
    for item, key in zip(items, keys):
        kmi = km.keymap_items.new(
            idname = "particle.select_brush",
            type = key,
            value = "PRESS",
            )           
        kmi.properties.brush = item[0]

    kmi = km.keymap_items.new(
        idname = "wm.call_menu",
        type = "TAB",
        value = "PRESS",
        ctrl = True
        )
    kmi.properties.name = "VIEW3D_MT_particle_edit_select_brush"


 

You can bind keys to call a menu or directly choose a specific brush.